In situ formation of magnetite reactive barriers in soil for waste stabilization
- Edgewood, NM
Reactive barriers containing magnetite and methods for making magnetite reactive barriers in situ in soil for sequestering soil contaminants including actinides and heavy metals, organic materials, iodine and technetium are disclosed. According to one embodiment, a two-step reagent introduction into soil takes place. In the first step, free oxygen is removed from the soil by separately injecting into the soil aqueous solutions of iron (II) salt, for example FeCl.sub.2, and base, for example NaOH or NH.sub.3 in about a 1:1 volume ratio. Then, in the second step, similar reagents are injected a second time (however, according to about a 1:2 volume ratio, iron to salt) to form magnetite. The magnetite formation is facilitated, in part, due to slow intrusion of oxygen into the soil from the surface. The invention techniques are suited to injection of reagents into soil in proximity to a contamination plume or source allowing in situ formation of the reactive barrier at the location of waste or hazardous material. Mixing of reagents to form. precipitate is mediated and enhanced through movement of reagents in soil as a result of phenomena including capillary action, movement of groundwater, soil washing and reagent injection pressure.
- Research Organization:
- Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)
- DOE Contract Number:
- AC04-94AL85000
- Assignee:
- Sandia Corporation (Albuquerque, NM)
- Patent Number(s):
- US 6527691
- OSTI ID:
- 875082
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
formation
magnetite
reactive
barriers
soil
waste
stabilization
containing
methods
sequestering
contaminants
including
actinides
heavy
metals
organic
materials
iodine
technetium
disclosed
embodiment
two-step
reagent
introduction
takes
step
free
oxygen
removed
separately
injecting
aqueous
solutions
iron
ii
salt
example
feclsub2
base
naoh
nhsub3
11
volume
ratio
similar
reagents
injected
time
12
form
facilitated
due
slow
intrusion
surface
techniques
suited
injection
proximity
contamination
plume
source
allowing
barrier
location
hazardous
material
mixing
precipitate
mediated
enhanced
movement
result
phenomena
capillary
action
groundwater
washing
pressure
aqueous solution
capillary action
situ formation
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